The methanol steam reforming (MSR) reaction was studied by using both a dense Pd-Ag membrane reactor (MR) and a fixed bed reactor (FBR). Both the FBR and the MR were packed with a new catalyst based on CuOAl2O3ZnOMgO, having an upper temperature limit of around 350 degrees C. A constant sweep gas flow rate in counter-current mode was used in MR and the experiments were carried out by varying the water/methanol feed molar ratio in the range 3/1-9/1 and the reaction temperature in the range 250-300 degrees C. The catalyst shows high activity and selectivity towards the CO2 and the H-2 formation in the temperature range investigated. Under the same operative conditions, the MR shows higher conversions than FBR and, in particular, at 300 degrees C and H2O/CH3OH molar ratio higher than 5/1 the MR shows complete methanol conversion. (C) 2008 Elsevier B.V. All rights reserved.